Canon XC10

Canon XC10 July 2015

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EBU - Tech 3335 : Methods of measuring the imaging performance of

television cameras for the purposes of characterisation and setting

Alan Roberts, July 2015

SUPPLEMENT 17: Assessment of a Canon XC10 camera

Tests have been conducted in line with EBU R.118. This document is a report of the results of

the tests defined in Tech3335 and is not an endorsement of the product.

This is a report on tests carried out on a Canon XC10 camera, serial number 953054000076, a European

version. It closely resembles a small DSLR rather than a conventional television camera, but has an integral

lens and no monocular viewfinder. However, a monocular viewfinder can be simulated by using an

accessory mirror-box adaptor on the LCD touch-screen display, but this prevents access to some control

functions which are operated only on the touch-screen.

According to the specification, the sensor is a single large-format CMOS with the Bayer pattern of photo-

sites; 8.29Meg for video (3840x2160), 12Meg for stills (4,000x3,000), and nominally 1” size. Further

information from Canon reveals that the full sensor is 4224x3164, actually 16.8mm diagonal. Thus the full

sensor dimensions are 13.48x10.10mm and the photo-sites are spaced at 3.192 microns, giving a photo-site

area of 10.19 square microns, about 40% of that of a conventional ⅔” camera. The video image (both 4k and

HD) is made from a central 3840x2160 part which must be 12.26x6.89mm and 14.1mm diagonal. The

effective photo-site size for HD is 6.38 microns square, similar to that of a conventional ⅔” camera.

The lens is fixed (not inter-changeable) with a 10:1 zoom range from 27.3 to 273mm (35mm equivalent).

Maximum aperture is F/2.8 and ramps to about F/5.6 at the long end of the zoom. It has a manual zoom ring

and a focus ring which is disabled in ‘auto-focus’ mode, so is not calibrated.

All recording is 8-bit MPEG4 AVC/H.264 4:2:2. HDTV recording is onto SDHC card (long-GoP, at 50Mb/s

for 50P, 35mB/s for 25P or 25I), 4k recording is onto CFast card (3840x2160 intra-frame at 305Mb/s for

50P, 205Mb/s for 25P). Recording can also be done ‘off-speed’ between 4 and 1/1200 times normal, and

there’s a 5-second cache for pre-recording (only in HD).

The camera weighs 1kg with the internal battery (7.2v) and consumes 6.2W when recording 4k, 5.4W when

recording HD. The removable battery is 1.865Ah (14Wh) so should last at about 2.5 hours in normal video

use. The battery can be charged in the camera or in an external charger.

There are connectors for HDMI output (disabled when Wi-Fi is enabled), USB for file transfer, 3.5mm

microphone, 3.5mm headphone.

Controls include three assignable buttons. The right-hand side hand-grip can be swivelled up to ±90°.

Monitoring is done on a 3” LCD panel of ‘approximately 1,030,000 pixels’ (about 64x43mm, implying

about 1240x830 pixels). It can be swivelled up or down nearly 90° and the image can be enlarged 2:1 for

focusing. Most of the camera control is via this display as a touch-screen, although the system controls are

via a menu system driven by buttons on the hand-grip. Since the touch-screen is capacitative, it responds

only to fingers, not finger-nails or styli. Also, the accessory mirror-box prevents access to the screen.


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EBU - Tech 3335 : Methods of measuring the imaging performance of

television cameras for the purposes of characterisation and setting

Alan Roberts, July 2015

SUPPLEMENT 17: Assessment of a Canon XC10 camera

Many of the menu items have little or no effect on image quality. Those that have significant effect are

highlighted. Control of the camera is split between ‘proper’ menus and item-by-item control from the touch

screen. In boxes with a range of numeric settings, the values indicate the range, and no scales are given.

Default settings, where known, are underlined. Only settings relevant for video shooting are listed here,

although many operate for video shooting, replaying and photo modes. All measurements were made using

Manual mode.

The tested camera was an E version which has items related to 50Hz, the U version (NTSC) has items related

to 59.94Hz and drop-frame timecode. Only the E version is covered here.

In the tables, items that have an important effect on picture appearance are highlighted with grey

background. Rather than making recommendations for settings, I have included measurement results from

which the user can make his own decisions.

This is not intended as a replacement for reading the manual.

1. Switches, Connectors and Menu settings

Switches and connectors

Left side Focus Manual/auto switch

Disp. (Assign 1) Cycles screen info

Push AF (Assign 2) Find auto focus

Mic 3.5mm stereo input

HDMI out Video, disabled if WiFi enabled

USB Computer connection

Handle top Start/Stop Traditional red button

Photo/Video Mode switch

Wheel Asignable rotary control

On/Off Power button

Play Playback start/stop

Shooting mode dial

Manual, Av (aperture priority), Tv (shutter priority), P (program AE),

Auto, Scn (special scene)

Handle back Magnify (Assign 3) LCD enlarger, x2

Menu button

Menu joystick

Handle right Headphone 3.5mm stereo output

Bottom back Memory card slots

Battery compartment

Menu settings Access by menu button or touch screen. Select/set via joystick or

touch or drag relevant part of the screen. Submenus are indented.

Camera setup

Item Mode Range Description Face detection & tracking MAvTvPScn On, Off Not tested

Auto slow shutter PAv On, Off Blurs in low light

ND filter All On, Off 3 stops, x1/8

Flicker reduction All Auto, Off Reduce lighting flicker

Auto ISO limit or AGC

limit AvTvP

Auto, ISO or

Auto, dB

Set max ISO160~4000 or

Gain 0dB ~ 28.5dB


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Shockless WB All On, Off

Onscreen markers All

Off, Level (white), Level

(grey), Grid (white), Grid

(grey)

Level is mid-high horizontal,

Grid is 3x3

Focus ring direction All Normal, Reverse

Focus ring response All Fast, Normal, Slow

ISO/Gain All ISO, Gain Changes some menu items

Gain increment All Normal, Fine

Recording setup

Item Mode Range Description 4k/HD All 4k clips, HD clips Also on screen, bottom left

4k recording All 25p/305Mb/s, 25p/206Mb/s

HD recording All 50p/50Mb/s, 50i/35Mb/s,

25p/35Mb/s

Slow & Fast motion1 All

4k Off, x2, x4, x10, x20, x60,

x120, x1200 Also on screen, bottom right

HD Off, x1/4, x1/4, x2, x4, x10,

x20, x60, x120, x1200

Available space in memory All Reports on cards

Initialize All CF, SD Format memory cards

Timecode mode All Preset, Regen

Timecode running mode All Recrun, Freerun

Initial timecode All hh:mm:ss:ff Set the timecode

User bit type All Setting, Time, Date

Color bars All Off, EBU, SMPTE Swap EBU for ARIB in the U

version

1kHz tone All -12dB, -18dB, -20dB, Off Tone with bars

File numbering All Reset, Continuous

Audio setup

Item Mode Range Description Headphone volume All 0~8~15

Notification sounds All 0~8~15 Beeps for self-timer etc

Built-in mic wind screen All Auto (high), Auto (low), Off

Custom audio only

Built-in mic att All Auto, On, Off

Built-in mic freq response All Normal, Boost LF, Low cut,

Boost MF, Boost HF+LF

Built-in mic directionality All Mono, Normal, Wide

Mic Att All Auto, On, Off

Only when external audio is

plugged in

Mic low cut All On, Off

Mic terminal input All Line, Mic

Audio limiter All On, Off

Audio compressor All High, Low, Off

Wi-Fi setup

Item Mode Range Description Browser remote All Off, On Must be Off to enable HDMI

Browser connection

settings

All Set camera ID and port

Smartphone connection All

Access point connection All

Display MAC address All

________________________________________________________________________________________________ 1 Slow & Fast recording is not quite what it seems, e.g. x1/4 means recording 4 times over-speed, and setting 50p at

50Mb/s the camera will run at 25p and recording is at 18Mb/s. Beware, check other settings such as shutter speed to

make sure that recordings will be sensible.


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System setup

Item Mode Range Description Language All For the menus (English) Lots of languages

Time zone/DST All Lots of cities (Paris) Also Summer time On, Off

Date/Time All

Date/Time All Enter date and time

Date format All YMD, MDY, DMY MDY in U version

24 hour All Select Changes time to am/pm or

24h

LCD brightness All Horizontal scale Shows greyscale to help

LCD backlight All H, M, L

Fan All Auto, On The fan is very quiet

Wireless remote control All On, Off

Tally lamp All On, Off

Auto power off All On, Off 5 minutes to auto power-off

Assign button 1

Assign button 2

Assign button 3

All

Disp, Push AF, Magnification,

Zebra, Peaking, Digital tele-

conv, Powered IS, ND

filter,Start/stop, Photo

Default is 1=Disp, 2=Push

AF, 3=Magnifcation

Control Dial All Iris, Shutter, ISO/Gain Rotary control near Start/Stop

Customize FUNC menu All

Aperture, Shutter, Gain/ISO,

White balance, Mic level,

Exposure lock, AE shift,

Zebra, Peaking, Powered IS,

Digital tele-conv, Focus,

Magnification

Add/remove items from the

FUNC menu, display top right

Batt info All Display battery info

HDMI timecode All On, Off

HDMI rec command All On, Off

HDMI status All Display only

Distance units All Metres, Feet

Backup menu settings All Save, Load Saves menu to SD card

GPS auto time setting All Off, Auto update

GPS information display All Display

Certification logo display All Display

Firmware All Display

Reset all All No, Yes Full reset

Touch screen controls Submenus are indented.

Item Mode Range Description

FUNC Vertical list, right-hand side

Iris MAv F/2.8~F/11 In ¼ stop steps. Max aperture

reduces with zoom

Shtr MTv ½~1/50~1/2000 Shutter, 4 steps per factor of 2

ISO/GAIN2 M

Look

1,2,4

ISO 160~20000ISO

ISO stops 3 steps per factor of

2, GAIN in 1.5dB steps

GAIN 0~42dB

Look

3,5

ISO 500~20000ISO

GAIN 9~42dB

WB MAvTvPScn

Automatic, Daylight, Shade,

Cloudy, Flourescent,

Fluorescent H, Tungsten, K,

User 1, User 2

White balance. K can be set

2000 to 15000. User setting

are auto

Mic level MAvTvPScn Auto, Manual Manual can be set 0~100

Exposure lock AvTvPScn Manual, Off Manual can be set -3~+3

stops in ¼ steps

________________________________________________________________________________________________ 2 Noise is good up to 6400ISO (31.5dB) but the picture softens significantly above 1600ISO (19.5dB)


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AE shift AvTvP -2~0~+2 Stops in ¼ steps

Zebra All Off, 70,100 70%/100%

Peaking All Peak, Peak off Make sharp edges red in LCD

Powered IS All On, Off Image stabiliser

Digital tele-conv3 All On, Off X2 lens magnification

Focus3 All Touch spot to focus

Magnification3 All Off, On Touch to select area

FUNC

Vertical list, left-hand side

Look/Scn4

MAvTvP

1 Standard, 2 EOS Std, 3

Wide DR, 4 Cinema EOS Std,

5 Canon log, User 1, User 2

2 is too vivid, 5 needs post

Scn

Portrait, Sports, Night, Snow,

Beach, sunset, lowlight,

Spotlight, Fireworks

Audio scene All

Standard, Music, Festival,

Speech, Meeting, Forest &

birds, Noise suppression,

Custom

Metering mode AvTvP Standard, Spotlight, Backlight

Self-timer5 All Off, 2 sec, 10 sec

Image stabilizer All Off, Standard, Dynamic

Pre Rec6 All On, Off 5 second pre-rec

Other FUNC controls

Item Mode Range Description HD/4k All 4k clips, HD clips Bottom left of screen

Slow & Fast motion1 All

4k Off, x2, x4, x10, x20, x60,

x120, x1200 Bottom right of screen

HD Off, x1/4, x1/4, x2, x4, x10,

x20, x60, x120, x1200

________________________________________________________________________________________________ 3 Item not available unless specifically added via ‘Customize FUNC menu’

4 Standard has good knee for general purpose shooting, EOS Std is too vivid, 3 4 and 5 have a more gentle knee for a

film-type look 5 Self-timer appears in the menu list but could not be enabled in the tested camera.

6 Pre-recording is available only in HD recording.


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2. Measurements

All measurements were made on frames captured onto a SDHC card for HD, CFast card for 4k. Images for

this document were extracted as BMP files or LZW-compressed TIF files using Edius 7.31 and Edius 8. I

shall use the EBU system of designating scanning standards. Live viewing was done on a 42” consumer

grade plasma Panasonic display with ‘studio’ settings. In this section,

2.1. Colour performance

A standard Colorchecker chart was exposed, using daylight. The camera was allowed to auto-white balance

and to auto-expose. Fig 1 shows the performance for the five standard ‘Looks’.

Look 1 (standard) is good for normal television, Look 2 (EOS vivid sharp and crisp) is quite vivid and over-

saturated, Look 3 (wide dynamic range) is desaturated and nice for a film look, Look 4 (EOS camera) is less

saturated but possibly a little too much, Look 5 (Canon Log, wide dynamic range for post-processing) is

under-exposed and under-saturated.

Choosing the right Look is a personal matter, but Look 1 is fine for normal TV, Look 3 is good for a film

look. The others are all acceptable but may bring problems with noise and/or saturation levels.

There was no response to infra-red, clearly there must be an IR-stop filter in the optical path. This augurs

well.

2.2. Resolution and aliasing

2.2.1. Resolution for 4K (UHD-1)

Tests were made at F/5.6. The usual zone plate test

chart was framed to fill exactly half the width and

height of the image. Thus the calibrated dimensions

should all be doubled.

Fig.2 shows one quadrant of the luma pattern which

now reaches the 3840x2160 limits of UHD-1, plus

one quadrant of the smaller pattern which now

reaches the 7680x4320 of UHD-2. The recording

was intra-frame at 305Mb/s, using Look 1.

The modulation is extinguished above 3000

horizontally, and 1700 vertically. There is fairly

strong diagonal aliasing which is inevitable with a

Bayer-patterned sensor. There is no evidence of any

aliasing above the limits of UHD-1, therefore either

the lens cannot resolve it or there is an optical low-

pass filter tailored to the limits of UHD-1.

Interestingly, the diagonal resolution exceeds both

horizontal and vertical extinction limits. This

implies that the Bayer-decoding is the limit, rather

than the optics, which in turn suggests that there is

probably no optical low-pass filter and it is the lens which is providing the spatial filtering.

(a) Look 1 (b) Look 2 (c) Look 3 (d) Look 4 ( e) Look 5

Figure 1 Colorchecker p/50

Figure 2 4k luma p/50


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Fig. 3 shows quadrants of red and green. The red pattern resolution is little different from the green, which

confirms that resolution is limited by the lens.

The resolution performance is acceptable for Tier 2, UHD-1, although 10-bit output is required for full

compliance and so this camera should strictly not be accepted for 4k broadcast. Aliasing levels are

acceptably low.

Fig. 4 shows how the resolution changes with the ‘Look’ setting. Clearly, there is a considerable drop with

Look 5, and the alias levels have dropped dramatically as well. However, the resolution in Look 5 only just

exceeds the limits of HD, and while it is likely that post-processing would restore much of the resolution loss

the alias level would probably also rise.

Figure 2 4k red and green, p/50

(a) Look 4 (b) Look 5

Figure 4 4k luma


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2.2.2. Resolution for HDTV

Exposures were made at F/5.2. The zone plate chart

was framed to exactly fill the image. The image for

1920x1080 HD comes from a 3840x2160 part of the

sensor, thus there seems to be no need to decode the

Bayer pattern since each of the red and blue sub-

patterns are 1920x1080, and the green sub-pattern

has two, spatially offset, patterns of 1920x1080.

However, this would cause serious aliasing since the

optical low-pass filter (if there is one) must be

tailored to the 4k performance of the camera.

Therefore we should expect to see the effects of

down-scaling in the HD performance, i.e. some

aliasing.

Fig. 5 shows luma quadrants in p/50 with sharpness

set to minimum, zero, and using ‘Look 1’, described

as ‘Standard image for shooting clips’. The main

quadrant reaches 1920x1080, 3840x2160 in the

smaller pattern. There is little or no aliasing. Vertical

resolution is significantly better than horizontal, the

extinctions appear to be at about 1700x1080. Since the photo-sites are square, there seems to be no reason

why resolution should not also be square, i.e. horizontal and vertical should be the same.

Fig. 6 shows red and green quadrants. Since the image is from the compressed video the red pattern should

not have the same resolution as the green. However, the difference is quite small but appears to be

symmetrical. Nevertheless, it is quite acceptable.

Fig 7 shows the luma part of the chart with detail set to the default value 3, and to maximum 7. The default

value seems a good compromise between aliasing and resolution, while the maximum setting is clearly not

acceptable for good HD. Note that the maximum setting also brings up aliasing beyond the limits of HD,

which will cause problems with motion in MPEG coding. This also shows that the optics do not block

frequencies beyond HD.

Figure 5 HD luma p/50, sharp=0

Figure 6 HD red and green p/50, sharp=0


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Ass for 4k shooting, the ‘Look’ setting affects the resolution. Fig.8 shows the same part of the chart with the

‘Look’ set to 4 (similar to Canon EOS cameras) and 5 (wide dynamic range and colours for post-processing).

The resolutions are clearly very different, Look 4 appears to be much sharper although there is an associated

risk of some aliasing.

Fig. 9 shows the resolution for interlaced HD, with standard sharpness and Looks 1 and 5. The re-sampling

process which generates the interlaced output does not filter out the vertical components sufficiently to avoid

serious aliasing.

(a) sharp=3 (b) sharp=7

Figure 7 HD luma p/50,


Figure 8 HD luma p/50, sharp=3


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2.3. Noise, Dynamic Range and Sensitivity

2.3.1. Noise, Dynamic Range and Sensitivity for HDTV

The camera was exposed to a 6-step grey scale, tungsten illuminated. Multiple exposures were taken to

explore the dynamic range at ISO800 (13.5dB Gain), shooting HD using Look1. Fig. 10 shows the result,

noise levels plotted vertically versus signal level. The solid line is a trend line through (or nearly through) the

luma points.

Conventionally, the noise level would be

expected to rise near black since the differential

gain applied by gamma correction affects the

noise level, but here it drops consistently. There

are several possible reasons, but it is hardly

worth exploring these since the user has no

control over the noise performance. The level

at 50% video is about -48dB which is the

qualifying level for EBU R.118 HD Tier 1.

However, since the noise level falls from this

level towards black, the pictures look rather

less noisy than these figures imply.

Next, the camera was exposed to achieve 50% luma level

over the full range of ISO settings. Exposure was

controlled using the shutter and iris. Fig. 11 shows the

result, plotting the noise level versus the ISO setting

expressed in dB, with 0 being ISO 160. The ‘normal’

curve for this test would be a linear slope, rising by 3dB in

noise level with each 6dB in gain. The deviation from this

ideal indicates that there is some signal processing,

probably noise reduction, going on which is one of the


Figure 9 HD luma i/25, sharp=3

-62

-60

-58

-56

-54

-52

-50

-48

-46

-44

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1

Figure 10 HD noise profile, p/50 Look 1, ISO 800

-51

-50

-49

-48

-47

-46

-45

-44

-43

-42

-41

0 6 12 18 24 30 36 42

Figure 11 HD noise vs gain setting at 50% video


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possible reasons for the unconventional shape in Fig. 9. Nevertheless, the noise level of -48dB is held up to

32dB gain, which is the equivalent of ISO 6400.

A more likely reason for the unusual noise levels is a change in resolution with ISO setting. Fig. 12 shows

this clearly. Resolution drops considerably at the higher speed settings, so speeds higher than about ISO1600

(19.5dB) gain) ought not to be regarded as full HD even though the noise level is acceptable.

For dynamic-range measurements, multiple exposures were made of a Colorchecker chart at ISO 400

(7.5dB) using Look1, aiming to record exposures at which the white patch was just clipped, and the black

patch only just discriminable. These extremes were met with exposure difference of 80:1. The reflectances of

the white and black patches are 90.01% and 3.13% respectively, a ratio of 28.76:1. Thus the total dynamic

range must be about 2,300:1 about 11¼ stops. The same data was used to explore the opto-electronic

(gamma) curve, which appears to be the standard ITU.709 curve up to about 50% output level then curving

gently through a knee into a lower slope and reaching clipping level at about 450% exposure level. Thus this

curve appears to be able to cope with about 2.12 stops of headroom.

For comparison, the same test was done using Look5 and ISO500 (10.5dB) which was expected to have a

much wider range. The exposure difference was again 80:1, again making a total dynamic range of about

2,300:1. This is a surprise, since it implies that the only advantage in using the Looks is in the distribution of

this, apparently fixed, dynamic range. Again, the same data can be used to explore the gamma curve, and

again the curve is very like the ITU.709 curve up to about 40% output, then curving through a knee to reach

about 450% exposure level, about 2.12 stops of headroom, the same as for Look 1. Fig.13shows the curves.

For sensitivity calculations, more multiple exposures were used to find the aperture setting at which the peak

white patch reached 100%, when illuminated at 2000 lux. The camera was set to ISO800 (13.5dB gain) and

Look1, 1/25 second exposure. The signal levels are not clipped at 100% video level and it was simple to find

an exposure which reached exactly 100%, at between F/6.7 and F/7.3. So the sensitivity must be about F/5 at

(a) ISO 400 (7.5dB) (b) ISO6400 (32.5dB) (c) ISO 20000 (42dB)

Figure 12 HD zone plate softening with ISO setting, i/25 Look 1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

0 1 2 3 4 5

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

0 1 2 3 4 5


Figure 13 gamma curves


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ISO800 and 1/50 exposure. However, since the gamma curve of Look1 reaches 100% video at 2.4 times the

exposure at which a genuine ITU.709 gamma curve would reach 100% video, the aperture which would

cause 100% signal without this knee must be a factor of 1/2.4 less than measured, i.e. 1.55 stops less light, so

the lens aperture at which 100% video would be recorded without the knee must be about F/6.7 at ISO800.

2.3.2 Noise, Dynamic Range and Sensitivity for 4k

The camera was exposed twice to the 6-step

grey scale, at F/4 and F/11. This gives 12

points in a plot of noise versus signal level,

Fig.14.

The plot lines are trend lines through the

relevant points and thus are only approximate.

However, it is clear that the shapes are

different from those at HD, these curves are

much more like the conventional shape where

the noise level is roughly proportional to the

slope of the gamma curve. This implies that

the down-conversion process for deriving HD

pictures is acting as a filter rather than an

interpolator, which is highly desirable.

Next, the camera was exposed to the 6-step grey

scale again, using Look 1 and p/50. The ‘speed’

was set to 6 values from ISO 500 to 16,000. Fig.

15 shows the results. Clearly, as the speed rises,

the noise distribution rises further towards black,

but there is still an eventual down-turn near

black in each case.

Noise around mid-grey, the usual signal level for

categorisation of cameras, is much less affected.

Even at 16,000 ISO the mid-grey noise is

acceptable although the increase near black is

rather steep.

Fig. 16 shows the noise level at mid-grey versus

speed, expressed as gain in dB. The level is

better than -50dB (the target level for EBU

R.118 UHD Tiers 1 and 2) for all speeds below 36dB

gain. However, the rise in level near black (see Fig. 14)

makes the pictures look more noisy than this measure

would suggest when the camera is set to high

photographic speed. Nevertheless, the noise levels are

acceptable provided the photographic speed is set not

greater than about 10,000 ISO or 24dB gain.

Fig. 17 shows how the resolution changes with speed.

For this test, the zone-plate chart was framed to fill the

image, i.e. the dimensions of the larger quadrant at

1920x1080 and the smaller 3840x2160. It shows that the

higher speeds cannot be properly regarded as 4k

resolution, but are quite good for HD. So, shooting at up

to about 10,00 in 4k is a good way to get HD performance using down-conversion from the full frame in

post-processing. The noise levels at 20,000 are unacceptable.

-55

-54

-53

-52

-51

-50

-49

-48

-47

-46

-45

-44

-43

-42

-41

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

500

1000

2000

4000

8000

16000

Figure 15 4k noise profiles

-55

-54

-53

-52

-51

-50

-49

-48

0 6 12 18 24 30 36 42

Figure 16 4k noise level at mid-grey versus camera

gain in dB

-59

-58

-57

-56

-55

-54

-53

-52

-51

-50

-49

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1

Figure 14 4k noise profile, Look 5, ISO 800


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2.4. Motion effects

The sensor has a conventional ‘rolling shutter’

process for readout, and so differentially

distorts objects moving in the frame. Fig. 18

shows parts of two frames from a sequence of

a small desk fan, the blades rotating such that

they appear to be almost stationary. The

distortion is quite obvious, and cannot be

corrected. This level of distortion is not

unusual in cameras with a rolling-shutter.

2.5. Conclusion

The recording coder bit-rates qualify the camera for all Tiers in R.118, however, the bit-depth is problematic.

The 4k resolution is limited by the optics, and there is some diagonal aliasing. The camera cannot officially

qualify for R.118 UHD-1 because the recording is 8-bit, whereas R.118 requires 10-bit or greater. Also,

R.118 demands interchangeable lenses for UHD-1. Nevertheless the noise performance meets the criteria for

both Tiers of UHD-1, and the 4k mode is a good way to shoot for HD production provided extreme speed

settings are not used.

The HDTV resolution and aliasing is good enough for the camera to qualify for R.118 HD Tier 1, as is the

noise level. It is only the monitoring and connectivity requirements which are not really met. Thus its

performance meets Tier 1, and it easily meets Tier 2L. It could be used in Tier 1 situations provided the

monitoring and connectivity problems can be dealt with.

There is no infra-red response, implying the presence of an IR-stop filter. Motion portrayal is affected by the

sensor rolling-shutter.

Figure 18 motion effects

(a) ISO 400 (b) ISO 6,400 (c) ISO 20,000

Figure 17 4k resolution, Look 1, 50mm, F/5.6

Canon XC10

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